Systems and methods that facilitate efficient and effective shadow image generation are presented. In one embodiment, a hard shadow generation system comprises a compute shader, pixel shader and graphics shader. The compute shader is configured to retrieve pixel depth information and generate projection matrix information, wherein the generating includes performing dynamic re-projection from eye-space to light space utilizing the pixel depth information. The pixel shader is configured to create light space visibility information. The graphics shader is configured to perform frustum trace operations to produce hard shadow information, wherein the frustum trace operations utilize the light space visibility information. The light space visibility information can be considered irregular z information stored in an irregular z-buffer.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An integrated circuit implemented system for generating a hard shadow, the system comprising: a compute shader configured to retrieve pixel depth information from a memory and to generate projection matrix information therefrom, wherein the compute shader is configured to generate said projection matrix information by performing dynamic re-projection from an eye-space to a light space utilizing the pixel depth information, wherein the dynamic re-projection includes: a first screen space pass which performs a quantized count of screen pixels mapped to a light pixel and said quantized count is included in a list, and a second screen space pass that utilizes the list to selectively identify sub-areas with particular screen pixel counts per light pixel that correspond to a threshold, wherein the selectively identified sub-areas are subsequently turned into new light space frusta which are associated with a new projection matrix.
2. The system of claim 1 , wherein the light space visibility information comprises irregular z information and is stored in an irregular z-buffer.
3. The system of claim 1 , wherein the performing dynamic re-projection comprises creating multiple projection matrices based on density of pixel projections in an area of a light space grid.
4. The system of claim 1 , wherein a first projection matrix comprises a subset of a portion of initial projection information and wherein the subset further corresponds to a portion of a light space grid where a density of pixel projections exceeds a predetermined threshold.
5. The system of claim 1 , wherein the light space visibility information comprises list head information.
6. The system of claim 1 , wherein the performing frustum trace operations comprises determining if a pixel is within a frustum.
7. The system of claim 1 , wherein the performing frustum trace operations comprises: defining a frustum projected from a grid cell corresponding to a light source in light space; determining that a graphics primitive intersects the frustum; and accessing a light space visibility buffer to obtain a set of pixel fragment footprints corresponding to the frustum and identifying whether a pixel fragment footprint within the set of pixel fragment footprints is shadowed by the graphics primitive.
8. The system of claim 1 , further comprising: a pixel shader configured to generate light space visibility information; and a graphics shader configured to perform frustum trace operations to generate hard shadow information, wherein the frustum trace operations utilize the light space visibility information.
9. A computer implemented method of performing dynamic re-projection, the method comprising: generating an initial projection list; determining a subset of light space grid cells in which the initial projection list indicates that a number of pixels that are collectively mapped to the subset of light space grid cells exceeds a predetermined threshold; and performing dynamic re-projection of a subset of the pixels corresponding to the subset of light space grid cells, the dynamic re-projection generating a re-projection list that corresponds to the subset of the pixels spread out across a wider light space area than in the initial projection list.
10. The method of dynamic re-projection of claim 9 , wherein said performing dynamic re-projection comprises spreading out the subset of pixels to a light space grid with a same number of light space grid cells as an initial light space grid.
11. The method of dynamic re-projection of claim 9 , further comprising generating a plurality of matrices based upon the dynamic re-projection.
12. The method of dynamic re-projection of claim 9 , further comprising generating a plurality of matrices based upon results from the dynamic re-projection.
13. The method of dynamic re-projection of claim 12 , wherein the plurality of matrices comprises: a first matrix corresponding to a projection of an original set of pixels minus the subset of pixels; and a second matrix corresponding to the dynamic re-projection of the subset of pixels.
14. The method of dynamic re-projection of claim 12 , further comprising creating a projection matrix buffer operable to store in memory multiple projection matrices associated with the dynamic re-projection.
15. The method of dynamic re-projection of claim 9 , wherein the subset of pixels corresponds to a hot area with respect to a number of pixels mapping to an area of a light space grid.
16. The method of dynamic re-projection of claim 9 , wherein the performing dynamic re-projection results in a number of pixels projected to a light space grid being quadratically reduced which reduces a length of a list corresponding to a projection of the pixels.
17. An electronic system comprising: a processor configured to perform operations comprising hybrid frustum trace shadow operations to generate results comprising a shadow effect, wherein the hybrid frustum trace shadow operations comprise: dynamic re-projection operations responsive to a number of screen pixels mapped to a light pixel exceeding a threshold, wherein the dynamic re-projection operations include creating a re-projection matrix by applying a subset of an original projection matrix to a similar height and width texture grid in light space as an original texture grid and spreading out pixels of the subset to a wider area than in the original projection matrix; and frustum tracing operations; a memory configured to store information for the processor, wherein the information comprises information associated with hybrid frustum trace shadow operations; and a display configured to render shadows in accordance with the shadow effect.
18. The electronic system as described in claim 17 , wherein the processor is further operable to render anti-aliased hard shadows in real-time using a light space visibility buffer generated utilizing the results.
19. The electronic system as described in claim 18 , wherein the processor is further operable to avoid introduction of spatial and temporal aliasing operations.
20. The electronic system as described in claim 18 , wherein said buffer is stored in said memory.
21. The electronic system as described in claim 17 , wherein a lerp factor is applied to the frustum tracing operations for generation of hard shadow information.
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March 15, 2018
August 18, 2020
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